LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
AutoTURN - AutoTURN is used to confidently analyze road and site design projects including intersections, roundabouts, bus terminals, loading bays, parking lots or any on/off-street assignments involving vehicle access checks, clearances, and swept path maneuv…
FreeCAD - An open-source parametric 3D modeler
AutoCAD MEP - AutoCAD MEP software helps you draft, design, and document building systems.
gCAD3D - 3D - CADCAM - Software for MS-Windows and Linux. Freeware
MicroStation - 3D CAD modelling software for architecture and engineering.